Preheat an oven to 375°F. Line a 12 standard muffin tin with paper lines or brush the insides of the cups with oil.
To make the muffins, in a bowl, stir together the flours, sugar, baking powder, baking soda, cardamon, lemon zest and salt.
In a small mixing bowl combine the yogurt, egg, melted butter, and vanilla.
Add the wet ingredients to the dry. Stir together for a minute, the batter will be slightly lumpy.
Add the blackberries and gently fold in with a large rubber spatula just until evenly distributed.
Spoon the batter into the prepared muffin cups. Top each muffin with the almond crumble topping.
Bake for 25 to 30 minutes, rotating halfway through. The muffins are done when they are golden on top, and a toothpick inserted into the center comes out clean.
Transfer the pan to a wire rack and let cool for 10 minutes. Unmold the muffins.
Almond Crumble Topping
To make the topping, in a small bowl, stir together the sugar, flour and lemon zest. Stir in the melted butter until the mixture is crumbly. Add the almonds and stir to combine.
Notes
You will need 1-2 lemons for this recipe.
Cinnamon can be substituted for cardamon for a more traditional flavor.
Optional Lemon Glaze
Mix together 1 cup confectioners sugar (powdered sugar) and 2 to 3 tablespoons of lemon juice. Drizzle over muffins.